Upgraded AHS Wellbeing Through the Joining of Vehicle Control and Correspondence

Presentation Transcript

Improved AHS Safety Through the Integration of Vehicle Control and Communication October 2002 J. K. Hedrick, R. Sengupta, Q. Xu, C. Lee, Y. Kang

Communication engineering Goal = remote system valuable for: 1) Cooperative grinding estimation 2) Cooperative Emergency Maneuver 3) AHS and agreeable versatile journey control Emergency Braking Maneuvers Tire/street rubbing estimation Goal: Develop a sheltered control technique for the crisis braking move of detachments. Objective: Real time estimation of greatest tire-street grinding Research Areas

Communication design Tire/street rubbing estimation Road Condition & Maximum Friction Coeff. Data from different vehicles and street side infra structure. Crisis Braking Maneuvers " SAFETY " Project Goals

Slip-based Road Condition Estimation

Overview and Benefits of the Research Overview Empirical approach Effect-based technique Real Time work Benefits Estimation of max. increasing speed point of confinement of the vehicle. Crisis Braking Control for the Platoon. Street Condition versus Position Map.

Slip/Friction Coefficient Calculation Friction Coefficient Slip Max Acceleration Maximum erosion coefficients decides most extreme speeding up or deceleration

Slip Slope Vs ��  Affecting Factors Road Condition Tire Type Tread Pattern Tread Depth Velocity ��  Focus on Linear Region �� Slip Slope, k

Schematic of the Estimator

Static Normal Force Observer Normal Force �� friction coefficient figuring �� effective tire span estimation Static typical constrain spectator expect a static model for vehicle�� 3% blunder contrasting with element vehicle show Static Normal Force Model

Effective Tire Radius Observer Tire range is required for Slip Calculation Tire Radius Change is a Function of Normal Force Tire Pressure Velocity

Tractive Force Estimation

Brake Gain Estimator Brake Gain Change Heat Water Wear of Brake Pad, and so on �� sometimes changes more than half Model : Front Wheel Dynamics Method : Recursive Least Square Method Using Bounded Forgetting

Slip Slope Vs Each vehicle has its own slip slant under same street Dry street condition �� set as Reference slip slant Maximum rubbing coefficient change rate/Slip incline change rate in view of reference slip slant �� Linear Assumption

Slip Slope and Estimation Example : Wet ��  Dry Slip Slope Estimation Using RLS technique Estimation Based on slip slant

Emergency Braking Maneuvers

Emergency Braking Controller (Longitudinal Control) Requirements for crisis braking Control power against the high slip condition amongst street and tire. Erosion coefficients estimation calculation. Control technique : Dynamic Surface Control

Experimental Set-up Experimental Vehicle utilized : Ford red Lincoln town auto Sensors and actuators : wheel speed sensors brake weight sensors 5 th wheel speed sensor brake and throttle actuators Computers with continuous OS : QNX working framework

Simulation Results Simulation with Dynamic Surface Control (6 m/s 2 deceleration)

Experimental Results Experiments in same circumstance ( 6 m/s 2 deceleration)

Analysis of the Result The execution of the Dynamic Surface Controller is sensible (1~2m blunder with –6 m/s 2 ) in a crisis braking circumstance. Control execution relies on upon erosion coefficients.  "Erosion coefficient estimation" is important.

( Emergency Braking Control Strategies for Platoons Emergency braking for the Platoons : Difference of max. deceleration constrain between vehicles can bring about impact. Agreeable Emergency Control. ) Vehicle with Worst Braking Capacity transmits its data.

Simulation Results Space & speed following [m/s] [m]